Self-Similarity Breeds Resilience
This work addresses resilience in systems for domains like security and reliability, but it appears incremental as it builds on existing formal methods without major breakthroughs.
The paper tackles the problem of proving resilience to adversarial behavior in systems by formalizing self-similarity, showing that for a specific class of systems, this problem is decidable using well-structured transition systems, and illustrating the framework with examples like fail-stop models and side-channel attacks.
Self-similarity is the property of a system being similar to a part of itself. We posit that a special class of behaviourally self-similar systems exhibits a degree of resilience to adversarial behaviour. We formalise the notions of system, adversary and resilience in operational terms, based on transition systems and observations. While the general problem of proving systems to be behaviourally self-similar is undecidable, we show, by casting them in the framework of well-structured transition systems, that there is an interesting class of systems for which the problem is decidable. We illustrate our prescriptive framework for resilience with some small examples, e.g., systems robust to failures in a fail-stop model, and those avoiding side-channel attacks.